Life cycle: Both species are annuals that reproduce by seed.
Plants are common in nurseries, landscapes, agricultural fields, and disturbed
sites. Rosettes form throughout early spring and summer. Flowers emerge
in mid- to late summer.
Below is a side-by-side comparison of the two most common species. Many
features are similar. They are most easily distinguished when observed
at the same time. Their differences are primarily the relative degree of
pubescense on each.
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C. setosa - Bristly hawksbeard |
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C. capillaris - Smooth hawksbeard |
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Rosettes grow up to 16 inches in diameter. Foliage is deeply lobed
near the leaf base, and deltoid in shape near the leaf tip.
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Rosettes are similar to those of C. setosa. |
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| Sparsely leafed stems emerge from rosettes. Plants grow 1 to 2 feet in
height. |
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On the basis of habit alone, plants are virtually identical. Two of
the three plants above are C. capillaris and one is C. setosa.
I forget which is which, the point is, they are very similar.
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| Stems of C. setosa are very hairy. |
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Stems are relatively smooth compared to those of C. setosa. Some pubescense
can be observed on close examination.
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Cauline leaves clasp the stem, are deltoid in shape, and lobed near the
base.
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Cauline foliage is similar to that of C. setosa. |
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| Flower buds and stems are very bristly or hairy. |
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Flower buds and stems are slightly pubescent, but far less than those
of C. setosa.
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Flower heads are yellow ray flowers. Heads are about 1 inch in diameter.
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Flower heads are virtually identical to those of C. setosa. |
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| Involucres occur in 2 series, each very hairy. |
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Involucres are similar to those of C. setosa, except they are much less
hairy. |